1. Field of the Invention
This invention relates to a novel process for the synthesis of both enantiomers of bicyclo[4.2.0]oct-2-en-7-one and intermediates therefor and their application to the synthesis of certain bicyclo[4.2.0]octane derivatives, useful for treating cardiovascular disorders.
2. Related Disclosures
A method for the synthesis of certain bicyclo[4.2.0]octane derivatives, useful for treating cardiovascular disorders, was disclosed in U.S. patent application Ser. No. 716,872, which is incorporated herein by reference. Three steps of this method involved separation of isomers from a diastereomeric mixture by (1) formation of a cobalt complex, (2) separation of this complex by chromatography and (3) conversion of the separated cobalt diastereomers back to the uncomplexed isomers.
It would be valuable to have a process for the preparation of the bicyclo[4.2.0]octane derivatives useful for treating cardiovascular disorders that did not involve the above three steps. A novel process has been discovered that achieves this end, by starting from resolved bicyclo[4.2.0]oct-2-en-7-one.
Subject matter related to the process of our invention is disclosed in U.S. Pat. No. 4,130,721, Tet. Lett., 1093-1094, 1986 and J.C.S. Chem. Comm., 908-909, 1979.